Slideway protection system in machine tools and the like



Sept. 8, 1964 R. DEFLANDRE SLIDEWAY PROTECTION SYSTEM IN MACHi NE TOOLS AND THE LIKE 2 Sheets-Sheet 1 Filed May 16, 1961 mm k R P' 1964 R. DEFLANDRE 3,148,003

SLIDEWAY PROTECTION SYSTEM IN MACHINE TOOLS AND THE LIKE Filed May 16. 1961 2 Sheets-Sheet 2 wulmwmw United States Patent 3,148,003 SLIDEWAY PROTECTION SYSTEM IN MACHINE TOOLS AND THE LIKE Ren Deflandre, Paris, France, assignor to Socit dite: Derefa, Etablissernent pour le Dveloppement, Recherches et Fabrications Indush'ielles, Vaduz, Liechtenstein Filed May 16, 1961, Ser. No. 128,281 Claims priority, application France, May 27, 1960, 828,333, Patent 1,267,192 9 Claims. (Ci. 308--3.5)

In machine tools and similar mechanical assemblies including relatively slidable machine components it is customary to provide protecting means surrounding the slideways against the ingress of dirt, metal cuttings and other foreign particles that would otherwise be liable to damage the precisely machined slideway surfaces. Such protecting means may comprise collapsible casings such as accordion-pleated bellows made of suitable plastic of leather, or telescopically interfitted metallic elements, in order to maintain an enclosure around the length of the slideways regardless of the relative position between the slidable components.

While such conventional protection means quite effectively prevent the ingress of large metal cuttings, they fail to provide adequate protection against smaller abrasive particles which are well capable of seriously damaging the slideway surfaces. Such particles find their way through the spaces and interstices present between the protective casing and sides of the slideways and/or between adjacent telescopic sections of the collapsible casing. Small metal particles are especially apt to enter during operation of the machine tool when a multitude of minute metal particles are floating in the air around the machine. When the machine as a whole is being cleared of cuttings the protecting covers of the prior art actually do more evil than good since they tend to collect the floating abrasive particles, prevent adequate visual check of the state of cleanliness of the slideways and interfere with the cleaning of the surfaces. In fact in view of this many users of machine tools prefer to remove such collapsible covers entirely and operate the machine tools without them, even though this means the necessity of very frequent cleaning operations and still does not prevent a shortening of the useful service life of the slideways.

It is an object of this invention to provide improved protection means for slideways in mechanical assemblies especially large-sized machine tools, which will provide a positive and effective protection against the entry of abrasive and other foreign matter without requiring practically any supervision. A broad object is to improve the surface condition of slideways and thus preserve high accuracy in machining operations and machine performance generally over prolonged periods of time.

The invention essentially contemplates means for permanently injecting gas, e.g. air, under superatmospheric pressure into an enclosure, such as a collapsible cover or casing of any of the aforementioned types, surrounding the slideway.

An exemplary embodiment of the invention will now be described for purposes of illustration but not of limitation with reference to the accompanying drawings where- FIGURE 1 is a side elevational view, with parts broken away, of a milling and boring machine to which the invention is applied;

FIGURE 2 is a section on line II-II of FIGURE 1;

FIGURE 3 is a corresponding plan view with the standard of the machine shown in section on line III-III of FIGURE 1;

FIGURE 4 is a larger scale view of a detail; and

3,148,003 Patented Sept. 8, 1964 FIGURE 5 is a partial view along the line 22 of FIGURE 1 and shows the blower intake line provided with an air filter instead of an elevated intake conduit as in FIGURES 1 and 2.

The milling and boring machine illustrated is of a conventional type including an elongated horizontal bed or bench 2, a standard 1 upstanding from and movable longitudinally of the bed on the longitudinal slideways 5, 6 and 7; a slide 4 displaceable vertically along the standard 1 on vertical ways 41, 42 and 43; and a milling and boring head 3 displaceable along the slide 4 on horizontal ways normal to the slideways 5, 6 and 7.

Collapsible protection means are provided for enclosing the slideways 5, 6, 7 of the bench, and include two sets of telescopically interfitted elements respectively designated 11a and 11b. The set of elements 11a extend from one end of the bench 2 to one side of standard 1 and the set of elements 11b extend from the other end of bench 2 to the other side of standard 1. Each set comprises a number of, e.g. seven, channel shaped sheet metal elements such as 12, 13, 14 15, having flanged sides slidably engaging side flanges 5 and 7 of the bench 2 and telescopically engaging one another; antifriction means may if desired be provided between the adjacent elements and between each element and the bench. FIGURE 1 shows the standard 1 positioned ator near its endmost right hand position, and accordingly the left hand set of cover elements 11a is completely expanded while the other set 11b is retracted or collapsed. It will be obvious that abrasive particles and the like are able to penetrate the casing structures 11a and 11b through gaps and interstices such as the gaps 21, 22, 23 between the adjacent channel elements and the gaps such as 24, 25 between the channel elements and the bench 2.

In accordance with the invention, air under superatmospheric pressure is discharged into the enclosures defined by the cover sections 11a and 11b around the bench slideways. For this purpose, referring to section 11a, a plurality of vertical longitudinally spaced air ducts 27 are provided within the bench 2 with their upper ends fitted with nozzles 28 opening upwards into apertures formed in the upper surfaces of the bench as clearly shown in FIGURE 3. Each air nozzle 28 has a butterfly valve 29 pivoted in it for adjusting the flow of airthrough it. All the air ducts 27 have their lower ends connecting with a manifold 31 extending along the base of the bench 2 and connected with the output line 32 of a blower 33 having a rising intake pipe 35 opening at its upper end at a substantial elevation so as to draw in air from a region of the atmosphere in the workshop that is substantially free from floating metal particles, or from the outer atmosphere. A cover 36 over pipe 35 prevents entry of rain. In respect to the other casing section 11b there is provided a similar arrangement including a blower 33a delivering into a manifold 31a with which connect the spaced vertical air ducts 270, all these parts corresponding to the correspondingly numbered parts earlier described.

In the embodiment shown the veritcal slideways 41, 42, 43 formed on a side of standard 1 are similarly provided with the improved protection means. The collapsible cover in this case is provided as an accordion-type casing of flexible material in two sections, an upper section 44:: extending from the top of the slide 4 to a point near the top of standard 1, and a lower section 44b extending from the bottom of slide 4 to a point near the base of standard 1. Although each casing section in this instance is substantially continuous, still there are interstices such as 47, 48 (FIGURE 3) between the sides of the casing and the standard which it is impossible to seal; abrasive metal particles are therefore liable to penetrate into the casing and damage the surfaces of slidea ways 41, 42, 43. According to the invention, a blower 51 is mounted near the top of standard 1 beneath a hood 52 formed with louvring 53 for the intake of air. The outlet pipe 54 of the blower is connected with a vertical manifold 55 extending down the standard and having one or preferably more air ducts 56 extending from a side of it and fitted with end nozzles 57 opening centrally of the side surface of the standard 1 in which the slideways 41, 42, 43 are formed. Each nozzle 57 has a pivoted airflow adjusting valve 58 in it.

The operation of the system described will be immediately apparent from the foregoing description and it will be evident that the superatmospheric pressure maintained in all of the collapsible covers or casings will elfectively prevent the entry of foreign materials including the many minute but abrasive metal particles produced during the operation of the machine and which otherwise constitute a serious menace to the proper surface condition of the slideways.

Clearly the invention may be embodied in may other ways than that shown. A common blower may be used for both collapsible casing sections associated with each slideway direction, or indeed a single blower may be used for all the slideways. As is shown in FIGURE 5 of the drawing, air filter or strainer means 35' may be provided for cleaning the air delivered by the blower or blowers into the casings, instead of or in addition to using elevated intake pipes such as 35. The covers or casings surrounding the slideways may be constructed otherwise than shown. The air nozzles may vary in number, position and construction. The invention is, of course, applicable to any type of machine, especially though not necessarily machine-tools, having relatively slidable machine components.

What is claimed is:

1. In a machine tool having a first component with slideway means formed on a surface thereof and a second component with complementary slideway means formed on a surface thereof for sliding displacement of the second relatively to the first component, the provision of extensible and retractible cover means attached to said components so as to define an imperfectly sealed enclosure adjacent said surfaces on each side of said second component, duct means formed in one of said components and opening into each of said enclosures, and air blower means connected with said duct means for maintaining superatmospheric pressure in each of said enclosures.

2. The invention claimed in claim 1, wherein said duct means comprise a plurality of spaced ducts opening into each of said enclosures.

3. The invention claimed in claim 1, including flow adjusting means in said duct means.

4. The invention claimed in claim 1, including an intake conduit connected with said blower and opening at a substantial elevation above said machine.

5. The invention claimed in claim 1, including air filter means connected in an intake of said blower means.

6. A machine-tool comprising a horizontal elongated bed; slideways formed on the upper surface of the bed; a standard having complementary slideways formed on the bottom surface thereof for sliding displacement of the standard along the bed; a pair of first extensible and retractible cover assemblies each having one end attached to an end of the bed and an opposite end attached to a respective side of the standard and having sides engaging sides of the bed whereby to provide a pair of enclosures with the upper bed surface, said enclosures being imperfectly sealed; a plurality of vertical air ducts Within said bed spaced longitudinally thereof and opening at spaced points of said upper bed surface; manifold means extending longitudinally of said bed and connected with lower ends of said ducts; and blower means connected with said manifold means for maintaining superatmospheric pressure in each of said enclosures and preventing the ingress of foreign particles into said enclosures.

7. In a heavy duty machine tool, in combination, an elongated support having provided on a surface thereof a plurality of longitudinally extending slideways, work or tool supporting means mounted for slidable movement on said slideways, a pair of extensible and retractable cover assemblies for protecting said slideways against metal cuttings from said machine tool and each having one end attached to said elongated support at a point beyond one end of the range of movement of said work supporting means on said slideways and having its other end attached to a respective side of said work supporting means, so that regardless of the position of said Work supporting means on said slideways, the latter will be completely protected against metal cutting by said cover assemblies and said work supporting means, said cover assemblies forming with said support surface a pair of extensible and retractable chambers separated by said work supporting means and containing the portions of said slideways beyond each side of said work supporting means, said cover assemblies being incapable of perfectly sealing said chambers and leaving gaps through which abrasive particles may pass from the ambient atmosphere into said chambers and onto said slideways, a plurality of air passages arranged in spaced relation along said elongated support and extending through said support and said surface thereof into communication with both of said chambers, certain of said passages being in continuous communication with only one of said chambers, and certain of said passages being in communication alternately with both of such chambers in the sliding movements of said work supporting means, and means for feeding air simultaneously to all of said passages and through the latter into both of said chambers and at a pressure above atmospheric sufiicient to prevent the ingress of abrasive particles from the ambient atmosphere, through the gaps left by said cover assemblies into such chambers and onto said slideways whereby the latter is completely protected against abrasive materials.

8. In a machine such as is defined in claim 7, in which the discharge end of each of said passageways is provided with a nozzle having associated therewith a valve for adjusting the flow rate of the air discharging through such nozzle into the associated chamber.

9. In a machine such as is defined in claim 7, in which said air feeding means comprises a blower arranged to supply air to said passages, and means protecting the intake of said blower against the entry therein of abrasive materials from the ambient atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 2,340,022 Shellenberger Jan. 25, 1944 2,375,408 Gallimore May 8, 1945 FOREIGN PATENTS 316,469 Great Britain Aug. 1, 1959 

1. IN A MACHINE TOOL HAVING A FIRST COMPONENT WITH SLIDEWAY MEANS FORMED ON A SURFACE THEREOF AND A SECOND COMPONENT WITH COMPLEMENTARY SLIDEWAY MEANS FORMED ON A SURFACE THEREOF FOR SLIDING DISPLACEMENT OF THE SECOND RELATIVELY TO THE FIRST COMPONENT, THE PROVISION OF EXTENSIBLE AND RETRACTIBLE COVER MEANS ATTACHED TO SAID COMPONENTS SO AS TO DEFINE AN IMPERFECTLY SEALED ENCLOSURE ADJACENT SAID SURFACES ON EACH SIDE OF SAID SECOND COMPONENT, DUCT MEANS FORMED IN ONE OF SAID COMPONENTS AND OPENING INTO EACH OF SAID ENCLOSURES, AND AIR BLOWER MEANS CONNECTED WITH SAID DUCT MEANS FOR MAINTAINING SUPERATMOSPHERIC PRESSURE IN EACH OF SAID ENCLOSURES. 